Commit d1419311 authored Mar 22, 2022 by Eric Dumazet Committed by Greg Kroah-Hartman Mar 28, 2022

llc: fix netdevice reference leaks in llc_ui_bind()



commit 764f4eb6846f5475f1244767d24d25dd86528a4a upstream.

Whenever llc_ui_bind() and/or llc_ui_autobind()
took a reference on a netdevice but subsequently fail,
they must properly release their reference
or risk the infamous message from unregister_netdevice()
at device dismantle.

unregister_netdevice: waiting for eth0 to become free. Usage count = 3

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: 赵子轩 <beraphin@gmail.com>
Reported-by: Stoyan Manolov <smanolov@suse.de>
Link: https://lore.kernel.org/r/20220323004147.1990845-1-eric.dumazet@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent c3fa6d19

net/llc/af_llc.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -311,6 +311,10 @@ static int llc_ui_autobind(struct socket sock, struct sockaddr_llc addr)
		sock_reset_flag(sk, SOCK_ZAPPED);
		rc = 0;
		out:
		if (rc) {
		dev_put(llc->dev);
		llc->dev = NULL;
		}
		return rc;
		}

		@@ -410,6 +414,10 @@ static int llc_ui_bind(struct socket sock, struct sockaddr uaddr, int addrlen)
		out_put:
		llc_sap_put(sap);
		out:
		if (rc) {
		dev_put(llc->dev);
		llc->dev = NULL;
		}
		release_sock(sk);
		return rc;
		}